Peptide YY dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Peptide YY is a gut hormone your body releases after meals, alongside GLP-1. Given by drip to 12 lean and 12 obese people, it cut how much they ate at a buffet by about 30 percent in both groups. The rat and mouse result it was built on failed when other labs tried to repeat it. Nausea kept it from becoming a drug.
Evidence grade for Peptide YY: Limited. The rule: people have taken it in a published study, but fewer than 100 of them. The sum on this page: 3 completed trials, 12 people given it. A grade counts how much has been done to people, not whether it works.
- People given it
- 12
- Human studies
- 3
- Found nothing
- 1
Dose
No human dose established
Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose.
3 completed trials, 12 people given it
3 effects reported, 2 unwanted, 1 wanted, by people using it, not a trial
Goal pages: Fat loss and metabolism, Ageing and longevity
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
Peptide YY is a gut hormone. Your gut lets it out after you eat, along with GLP-1. It tells your brain you have had enough. There is no approved drug made from it.
What people take it for
- Cutting appetite.
- Weight loss without a prescription drug.
- Stacking with GLP-1 style drugs.
What studies in people showed
The human studies are small and short. They gave it by drip and measured the next meal. In 12 lean and 12 obese people, eating at a buffet fell about 30 percent. Mixed with another gut hormone, eating fell 42.7 percent in 12 people. A pump giving three gut hormones for 10.5 hours cut eating by 32 percent. No study has tracked weight over months. In rats and mice, other labs could not repeat the first result. Nausea is what stopped it from becoming a drug. Nobody can patent the natural hormone, so no company has paid for a longer study.
What people report
Reports, not study results
The good
- In the drip studies, people ate less at the next meal, lean and obese alike.
The bad
- Nausea is the known problem at doses that cut eating.
- It wears off fast, and there is no published data behind how research chemical buyers dose it.
Where these come from: No user reports. These come from the small drip studies and reviews on this page.
My bottom line
One meal of eating less is not weight loss. The drugs that work on this system for real are the approved GLP-1 drugs. That is a talk for your doctor, not a vial from a website.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals Peptide YY has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Feeling less hungryno headcount stated · 2 studies · 1 found nothing
- Cell energy and mitochondriano headcount stated · 1 study · 1 found nothing
Animal and lab work, not yet tested in people
Real results, but from animals or cells, not people. What works in a mouse often does not work the same way in a person. Nobody can patent this, so nobody would ever earn back the cost of a study in people. That is usually why there is none. The record on this one is set out below.
- Losing weight1 animal or lab study
33 of the 36 indexed goals have no study of any kind behind Peptide YY
No study in people, animals or cells on this page reports a result for these. That does not prove Peptide YY does nothing for them. It does mean anything you have heard about Peptide YY and one of these did not come from a study cited here.
Show full evidence
What is Peptide YY?
Peptide YY is a gut hormone your body releases after meals, alongside GLP-1. Given by drip to 12 lean and 12 obese people, it cut how much they ate at a buffet by about 30 percent in both groups. The rat and mouse result it was built on failed when other labs tried to repeat it. Nausea kept it from becoming a drug.
Peptide YY is a gut hormone. The same gut cells that make GLP-1 and oxyntomodulin release it after you eat. The more calories in the meal, the more comes out. An enzyme called DPP-4 trims two pieces off the front. That makes the active form, PYY3-36. It acts on the hunger nerve cells in the brain and turns them down. Here is the key fact. The same enzyme that destroys GLP-1 switches PYY on.
The human studies are small and short. They gave the hormone by drip and measured the next meal. The results agree with each other. In a 2003 study, 12 obese and 12 lean people each got PYY3-36 one day and a salt water drip another day. Two hours later they ate at a buffet. The obese group ate 30 percent less, and the lean group 31 percent less. They also ate less over the whole day. Obese people had less PYY in their blood to begin with (10.2 against 16.9 pmol/L). But they responded to it just as well. That is the big difference from leptin, and it is why the paper mattered.
Later studies from the same London group went further. PYY3-36 plus oxyntomodulin cut eating by 42.7 percent in 12 overweight or obese people. That was more than either one alone. A 10.5 hour drip under the skin of GLP-1, oxyntomodulin and PYY cut eating by 32 percent. The doses matched the levels seen after gastric bypass surgery.
The fight is about the rodent work. A 2002 paper reported that PYY3-36 cut eating and weight gain in rats and mice. It also had a human part, where eating fell 33 percent over a day. In 2004, researchers from several separate labs reported that they could not repeat the rodent result. Both sides are set out below. The human drip result has been repeated. The rodent result is disputed. Neither one cancels the other.
No PYY drug is approved anywhere. Every human study measured eating over hours. None measured body weight over months or any health outcome. Nausea limited how much people could be given. PYY3-36 is sold by research chemical sellers and is not approved for any use.
How does Peptide YY work?
In people, given by drip: PYY3-36 at normal after-meal levels makes people feel less hungry and eat less for hours. It lowers ghrelin, the hunger hormone. It works just as well in lean and obese people. In rats and mice, though this part is disputed: PYY3-36 cuts eating through a receptor called Y2. Mice without that receptor do not respond. It quiets the brain's hunger cells, called NPY cells. That frees up nearby fullness cells, called POMC cells. Full length PYY acts on several Y receptors. Trimming by DPP-4 makes it prefer Y2. PYY also slows how fast food leaves the stomach and moves through the gut. That is its older known job, as the gut's brake.
What have studies in people found about Peptide YY?
A handful of small studies gave PYY by drip and measured eating over a few hours. Each person got the hormone one day and a dummy drip another day. The drop in eating has been repeated, alone and mixed with GLP-1 and oxyntomodulin. No study has tracked body weight over months. No study has tested a PYY product for any health outcome.
- NEJM 2003: 12 obese and 12 lean people each tried the hormone and a dummy drip. Eating at a buffet two hours later fell 30 percent in the obese group and 31 percent in the lean group. Eating over the whole day also fell, and so did the hunger hormone ghrelin. Obese people had less PYY to start with but responded normally.
- Diabetes 2010: 12 overweight or obese people. PYY3-36 plus oxyntomodulin cut eating at a test meal by 42.7 percent, more than either one alone.
- JCEM 2017: obese volunteers wore a pump under the skin for 10.5 hours, giving GLP-1, oxyntomodulin and PYY at after-bypass levels. Eating fell 32 percent. Calories burned at rest did not change.
- Nature 2002, human part: a drip at normal after-meal levels cut appetite, and eating over a day fell 33 percent.
- US trials register, searched 11 September 2026: PYY shows up in dozens of studies as a hormone being measured. No study giving a PYY product came up under that name.
What this does not tell you: All of this is short term. One drip, one meal, at most a day. Nothing shows PYY3-36 lowers body weight over weeks. Nothing shows it keeps working with repeated doses, or that it changes anyone's health. Nausea is the known problem that limits the dose. The studies used levels at or near what the body makes on its own. The biggest study had 24 people, and most came from one London group. PYY3-36 wears off fast. There is no published data behind the way research chemical buyers take it.
The state of the research
PYY has a reputation problem that GLP-1 does not. The reason is one published event.
A 2002 paper reported that PYY3-36 cut eating and weight gain in rats and mice, and cut eating in people. In 2004, researchers from a number of separate labs said they could not repeat the rodent result on eating. They said they did not know why. They argued that a weight loss idea built on a result that is hard to repeat was of doubtful value. The first authors and others blamed stress in the animals. The effect of PYY3-36 is small, and stress on its own cuts eating. The other labs did not accept that a real effect should be so fragile. The argument was never settled, and we do not settle it here. The rodent effect is disputed, full stop.
The human effect is a separate question, and it has held up. The 2003 study, the 2010 two-hormone study and the 2017 three-hormone study all found real drops in eating, using three different methods. What nobody has done is turn that into a drug. PYY3-36 causes nausea at doses that cut eating. It wears off fast. As a natural hormone, nobody can patent it. So the short studies were never followed by a weight loss study of the natural hormone. Drug makers moved on to long lasting, lab-built versions and to mixing PYY action with GLP-1 drugs. That is why PYY matters on this site mostly as a partner hormone. The gut releases it together with GLP-1 and oxyntomodulin. The drip studies that mix them are the body's own case for obesity drugs that hit several hormones at once.
The evidence, in charts
Fig. 1a · how many people
12people, across 1 study in people cited here
| Study | People | Share |
|---|---|---|
| New England Journal of Medicine 2003 | 12 | 100% |
The whole total is one study of 12. Counts are the number of people each study on this page says it signed up. That includes studies that only watched people and gave nobody the compound. 2 more studies in people give no headcount and are not counted here. Studies still signing people up are left out, and only studies cited on this page are counted.
Fig. 1b · evidence mix
3 of 8 sources here are studies in people. The rest are not.
- Study in people · done in people338%
- Animal study · done in animals225%
- Review of studies · sums up other studies338%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
The studies cover 7 different years, 2002 to 2017, counted from the list of sources on this page. The newest source on file is from 2017, more than five years ago. Research on it may have gone quiet.
Fig. 3 · legal status at a glance
US
Not approved
UK
Not approved
AU
Not approved
CA
Not approved
Not approved in any of the four countries shown. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 4 · how much does what
Nobody has tested different amounts in people
This chart would show how the effect changes as the amount goes up. For this compound, nobody has measured that in people. So we leave it empty. We will not borrow an animal chart and pretend it works the same in people.
Fig. 5 · what the molecule is
- Kind of compound
- Peptide
- Molecule weight
- 11,145 Da precursor (97 residues, UniProt P10082); PYY(1-36) is residues 29 to 64 and PYY(3-36) residues 31 to 64
- Half-life
- None on file
- Chain length
- 36 amino acidscounted from the chain below
YPIKPEAPREDASPEELNRYYASLRHYLNLVTRQRY
Stored as YPIKPEAPREDASPEELNRYYASLRHYLNLVTRQRY (PYY 1-36; PYY3-36 lacks the first two residues). The count above is of the amino acid letters only.
- Water-shy 13
- Water-loving 11
- Acidic 5
- Basic 7
One square per amino acid, left to right from the start of the chain, coloured by type. The type is a fact about the amino acid, not a finding about this compound.
The studies we cite
- Study in people2003Inhibition of food intake in obese subjects by peptide YY3-36
A single infusion of this gut hormone cut how much people ate at their next meal. Twelve obese and twelve lean volunteers each tried the hormone and a dummy infusion, in turn, without knowing which they were getting. Two hours later they were given a buffet lunch. Obese participants ate about 30% less on the hormone, lean participants about 31% less. They also ate less over the following day. Public money paid for the work.
12 obese and 12 lean participants, double-blind placebo-controlled crossover. Buffet lunch intake two hours after PYY3-36 infusion fell 30 percent in obese and 31 percent in lean participants (both p < 0.001); cumulative 24-hour intake also fell; ghrelin fell. Fasting PYY was 10.2 pmol/L in obese versus 16.9 in lean (p < 0.001) and correlated inversely with BMI (r -0.84). Non-US government funded.
- Study in people2010PYY3-36 and oxyntomodulin can be additive in their effect on food intake in overweight and obese humans
Two gut hormones together cut eating more than either one alone. Twelve overweight or obese volunteers each tried the combination, the single hormones and a dummy infusion, in turn, without knowing which. At a test meal during the combined infusion they ate about 43% less than on salt water, and less than on either hormone by itself. This was one meal in a laboratory, not weeks of living with it. Public money paid for the work.
12 overweight or obese volunteers, randomised double-blind placebo-controlled crossover. Energy intake at a test meal during combined PYY3-36 and oxyntomodulin infusion was 42.7 percent below saline and significantly below either hormone alone. Non-US government funded.
- Study in people2017The Effect of a Subcutaneous Infusion of GLP-1, OXM, and PYY on Energy Intake and Expenditure in Obese Volunteers
Copying the hormone mix that follows stomach bypass surgery cut food intake by about a third. Obese volunteers wore a pump under the skin for about ten and a half hours, delivering three gut hormones at post-surgery levels, or a dummy infusion. Each person tried both, in turn, and did not know which was running. They ate roughly 32% less on the hormones. Resting energy burn did not change, so the whole effect was on appetite. Public money paid for the work.
Single-blind randomised placebo-controlled crossover in obese volunteers: a 10.5-hour ambulatory subcutaneous infusion of GLP-1, oxyntomodulin and PYY at doses matching post-gastric-bypass levels (PYY 0.4 pmol/kg/min) cut food intake by a mean 32 percent with no change in resting energy expenditure. Non-US government funded.
- Review of studies2017Ghrelin, CCK, GLP-1, and PYY(3-36): Secretory Controls and Physiological Roles in Eating and Glycemia in Health, Obesity, and After RYGB
A review of how gut hormones control eating in normal people, in obesity and after bypass surgery. It judges PYY's natural role in making people feel full as less proven than GLP-1's.
Comprehensive physiological review of PYY3-36 secretion and action in health, obesity and after bypass surgery, including the assessment that its physiological satiation role in humans is less securely established than that of GLP-1.
- Review of studies2015PYY3-36: Beyond food intake
A review of what PYY3-36 does beyond appetite, such as gut movement, energy use and bone. Most of it is animal work.
Review of PYY3-36 actions beyond appetite, including gut motility, energy expenditure and bone, most of it from animal work.
- Review of studies2008The role of PYY in feeding regulation
A review written in the middle of the argument. It covers how PYY works on its receptors and the rodent results that did not agree.
Review written in the middle of the replication dispute, covering the receptor pharmacology and the discordant rodent data.
- Animal study2002Gut hormone PYY(3-36) physiologically inhibits food intake
Mostly in rats and mice. PYY3-36 cut eating and weight gain in rats. It cut eating in normal mice but not in mice missing the Y2 receptor. A small human part found that a drip cut eating by 33 percent over a day. The rodent part is the one other labs could not repeat.
Peripheral PYY3-36 inhibited food intake and reduced weight gain in rats, and inhibited intake in wild-type but not Y2 receptor knockout mice, with arcuate c-Fos induction and reduced hypothalamic NPY mRNA. A human arm reported that infusion at postprandial concentrations cut intake by 33 percent over 24 hours. The rodent arm is the one that failed replication.
- Animal study2004Physiology: does gut hormone PYY3-36 decrease food intake in rodents?
In rats and mice. Researchers from several separate labs said they could not repeat the 2002 result that PYY3-36 cuts eating and weight gain in rodents. They did not know why. On that basis, they doubted PYY3-36 as a way to treat obesity.
A Brief Communication from investigators at several independent laboratories reporting that they had been unable to replicate the rodent food-intake and weight-gain findings of the 2002 paper, stating the reasons for the discrepancy were undetermined and questioning the value of PYY3-36 as an anti-obesity approach on that basis.
Where to buy Peptide YY
No seller we track lists Peptide YY yet. We read sellers’ public product lists every week, and this section fills in as soon as one does. Every seller, graded
Common questions
Has Peptide YY been tested in people?
Yes. 12 people given it across 3 completed trials cited here, 1 of which found nothing. Peptide YY is a gut hormone your body releases after meals, alongside GLP-1. Given by drip to 12 lean and 12 obese people, it cut how much they ate at a buffet by about 30 percent in both groups. The rat and mouse result it was built on failed when other labs tried to repeat it. Nausea kept it from becoming a drug.
What is the Peptide YY dosage?
No human dose established. Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose. 3 completed trials, 12 people given it
Is Peptide YY FDA-approved?
Not FDA-approved. No PYY or PYY3-36 product is approved anywhere. Natural PYY3-36 has only been given to people in studies, by a slow drip into a vein or under the skin.
Does PYY3-36 reduce appetite in humans?
For a few hours, yes, in several small studies. Given by drip to 12 lean and 12 obese people, it cut eating at a buffet two hours later by about 30 percent. It also cut eating over the whole day. Mixed with oxyntomodulin, it cut eating by 42.7 percent in 12 people. No study has measured weight over months.
What is the PYY replication controversy?
A 2002 paper found PYY3-36 cut eating in rats and mice. In 2004, researchers from several separate labs reported that they could not repeat that rodent result. The fight is about the rodent work. The human drip result has been repeated in later studies. Neither result cancels the other.
Are obese people resistant to PYY the way they are to leptin?
Not in the 2003 study. Obese people had less PYY to begin with (10.2 against 16.9 pmol/L in lean people). But when given PYY3-36, they ate 30 percent less, the same as lean people. That was the main point of the paper.
Why is there no PYY drug?
Three things stopped it. It causes nausea at doses that work. It wears off fast. And nobody can patent the natural hormone. The short studies were never followed by a weight loss study of PYY3-36 itself. Drug makers moved to long lasting lab-built versions and to mixing it with GLP-1 drugs. Those are still experimental. No PYY product is approved anywhere.